You got it Mike. I tried 1/2 ounce seed on one sqft of low-quality turf and covering it with one pound of screened topsoil. It was on October 13, 2011 and temp was 65. Rain and cooler weather expected in the next 7 days.
I calculated the seed was about 30 pounds per thousand sqft.
I calculated the soil layer at about .16 of an inch. (about 1000 pounds per thousand sqft.) If a cubic yard weighs 3000 pounds that is about a third of a yard per 1000 sqft.

I do not normally topdress--no experience here.

And Smallaxe, I did try covering seed with grass clippings, plus fert, plus raked-in. Results were good, but double fertilizer, and 4 times the usual amount of seed, and rake-in, resulted in the best and thickest grass. Photos coming soon.

Thanks for your tests Riggle.
On the similar note, I have following questions:
1) Since the grass is already about 2-3 inches tall, when should I do my first lawn mowing of this new seeded lawn.
2) Should I leave the grass clippings or should I bag them. Reasons?

I've got the same question as bperl and would also like to know whether to rake up the straw I put down to cover the seed. I planted the seed about 3 weeks ago and the grass is now 3-4 inches tall - a mix of fescue and rye.

I've got the same question as bperl and would also like to know whether to rake up the straw I put down to cover the seed. I planted the seed about 3 weeks ago and the grass is now 3-4 inches tall - a mix of fescue and rye.

It depends on how much straw you put down... many times it does more damage to remove the straw then it does to let it decay and supply the ground with soil building OM... but usually it it placed poorly and there are large areas that are just dead zones becuz the clumps of straw only allow the growing of weeds...

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Now that I know that clay's texture(platelets) has nothing to do with water infiltration, percolation, or drainage,,, I wonder what does...
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It depends on how much straw you put down... many times it does more damage to remove the straw then it does to let it decay and supply the ground with soil building OM... but usually it it placed poorly and there are large areas that are just dead zones becuz the clumps of straw only allow the growing of weeds...

Thanks Smallaxe.
That's about what I figured, so I'm mostly planning to leave it except the areas where the grass isn't growing thru because it is a little thick.

Any idea about when the first mowing should be done?
Also, should I leave the grass clippings or should I bag them?

For me it is mow when I'm not sucking seed or dirt and the ground is relatively dry and stable... Newly seeded lawn on bare ground, can grow as long as nit doesn't flop over on its neighbor and start the suffocation process, then mowed high when the ground is solid... Sometims use a pushmower at the beginning...

Almost always leaves clippngs for mulching the ground, and holding down the soil...

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Now that I know that clay's texture(platelets) has nothing to do with water infiltration, percolation, or drainage,,, I wonder what does...
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